Kooks 2" longtube install pics

[RaycinSS]

Nice job! Thanks for posting, I will be doing the same very soon so your post was very timely. Looks and sounds great. Besides the headers and intake what are your other mods?

[joelster]

Originally Posted by OneBadZ/28

Did you reuse your factory header bolts and gaskets? Did you use any type of cat O2 simulators? Thanks in advance.

The Kooks headers came with Percy's soft aluminum gaskets, and a set of Stage-8 locking fasteners. They also came with o2 extensions for the front o2's.

[joelster]

Originally Posted by RaycinSS

Nice job! Thanks for posting, I will be doing the same very soon so your post was very timely. Looks and sounds great. Besides the headers and intake what are your other mods?

Just the tune. The car made 482/476 baseline. From around 3500-6500 it was solid on the factory tune, but below 3500 it was too lean and had too much timing. Mike found 10hp and 7ft-lbs just tweaking it a little bit, but the factory tune wasn't bad at all.

[RaycinSS]

Originally Posted by joelster

Just the tune. The car made 482/476 baseline. From around 3500-6500 it was solid on the factory tune, but below 3500 it was too lean and had too much timing. Mike found 10hp and 7ft-lbs just tweaking it a little bit, but the factory tune wasn't bad at all.

I'm assuming from the numbers the 482 baseline was before the tune but with the headers and intake on? Do you have a baseline completely stock?

[joelster]

I don't have a baseline completely stock, but Mike has tuned literally 100 LS7 cars in various states of tune. He's only had 1 car ever break 500 with just bolt ons. It was a heavily raced engine and had a few more bolt-ons like a TB and a CAI setup. Plus the engine had a lot of miles and was "loose". He figured mine was right where it should be, probably around 445-455 bone stock.

[Yessa]

Nice install. Thanks for posting.

[STALKER]

Originally Posted by joelster

The Kooks headers came with Percy's soft aluminum gaskets, and a set of Stage-8 locking fasteners. They also came with o2 extensions for the front o2's.

Nice install. Keep an eye on those gaskets though. They have been known to leak. Most shops use OEM gaskets.

[pzero]

Joe,

Did you use the factory H pipe or did you take that out. Looking at the pics, looks like it's out. Also did you use the factory muffler? Thanks for the post.

When you went for a drive say at 3000 rpm, when you let off the gas, does it pop and crackle on decel?

[joelster]

Originally Posted by pzero

Joe,

Did you use the factory H pipe or did you take that out. Looking at the pics, looks like it's out. Also did you use the factory muffler? Thanks for the post.

When you went for a drive say at 3000 rpm, when you let off the gas, does it pop and crackle on decel?

Factory H pipe is still there. The kooks mid pipes end a few inches past the o2 sensor from the pic shown. Yes I’m using the factory NPP cat back. It sounds great. Yes it does crackle and pop similar to when it was stock. It’s my understanding that the crackle you hear is unburned fuel igniting in the exhaust. Maybe it’s something else. Not sure if you could totally tune it out without going dangerously lean with the tune.

[pzero]

Joe, thanks for the comment. I've been trying to eliminate the crackle and pop, but like the loud choppy rumble with H pipe. When I close off the NPP valve, crackle and pop goes away and so does the loud choppy rumble. I've been reading others with headers and a x pipe set up and they say crackle and pop will be eliminated. I might just do that, change out the H pipe with a X pipe.

By the way seeing your original post picture of underside showing the full exhaust system, there's a jack missing on the driver side rear...is that illusion or am I getting old?

[joelster]

Originally Posted by pzero

Joe, thanks for the comment. I've been trying to eliminate the crackle and pop, but like the loud choppy rumble with H pipe. When I close off the NPP valve, crackle and pop goes away and so does the loud choppy rumble. I've been reading others with headers and a x pipe set up and they say crackle and pop will be eliminated. I might just do that, change out the H pipe with a X pipe.

By the way seeing your original post picture of underside showing the full exhaust system, there's a jack missing on the driver side rear...is that illusion or am I getting old?

There are 3 jackstands on the passenger side, and 1 jackstand and a jack on the driver side. The car is just so stiff that as soon as you get the front wheels off the ground the rear comes up as well.